This invention relates to a connector and, more specifically, relates to a connector having a structure for retaining fine coaxial cables.
Conventionally, in electrical connectors, there is a structure described in Japanese Unexamined Patent Application Publication (JP-A) H11-260439 (hereinafter referred to as Patent Document 1) as a structure for retaining a plurality of coaxial cables. A coaxial cable connector of Patent Document 1 is configured such that terminals, each having a U-shape in cross-section and each for fittingly supporting a corresponding one of outer conductors of coaxial cables that are exposed by partly cutting off coatings or jackets of the coaxial cables, are integrally arranged in a row to thereby achieve electrical connection of the coaxial cables collectively. Alternatively, by heating the jackets near connection portions or a terminal in-row arranging member integral with the terminals, end portions of the coaxial cables arrayed horizontally at a predetermined pitch are respectively fitted in the corresponding terminals without partly cutting the jackets. That is, the outer conductors exposed from the melted jackets contact the corresponding terminals so that electrical connection therebetween is collectively achieved. In this manner, this conventional coaxial cable connector has an advantage in that ground coaxial cables can be achieved easily and, yet, reliably.
As a conventional cable connector according to another example, there is one described in Japanese Unexamined Patent Application Publication (JP-A) 2001-307822 (hereinafter referred to as Patent Document 2).
The cable connector described in Patent Document 2 comprises contacts for connection to center conductors or core wires of fine coaxial cables, an insulator fixedly retaining the contacts that are press-fitted thereto, and a shell covering the insulator. The shell comprises a first shell member fixedly retained by the insulator and covering a lower surface of the insulator, and a second shell member fitted over a relatively rear part of the insulator and retained so as to be attachable and detachable. A retaining portion is provided for retaining coated portions of the coaxial cables cooperatively with the insulator in a sandwich manner. The second shell member is in contact with an outer surface of the first shell member.
The plurality of coaxial cables are arranged in a planar fashion while partly exposing outer conductors (shield wires), then the exposed portions of the outer conductors are sandwiched between a pair of metal ground bars, and soldering is carried out while heating them, thereby electrically connecting the outer conductors to the ground bars collectively. In this event, the state of the planar arrangement of the plurality of fine coaxial cables is maintained. The center conductor is exposed at the tip of each fine coaxial cable.
As described above, in the conventional connector, the soldering is implemented by heating the outer conductors, having no jacket thereon, of the fine coaxial cables while sandwiching them from their upper and lower sides between the metal plates.
However, in the conventional connector, although the outer conductors of the fine coaxial cables are electrically connected and mechanically retained by the use of soldering, the solder does not stay within a range to be connected by the use of soldering, the solder does not stay within a range to be connected by the metal plates, for example, the ground bars, but is raised in a draw-out direction of the cables along the outer conductors so that bendability of the fine coaxial cables is degraded in a range where the solder is raised.
Actually, in the use after mounting in the connector, when the cables are forcibly bent in the foregoing range where the solder is raised, the outer conductors are broken.
Further, although the surfaces of the ground bars electrically contact metal outer members provided in the connector, because a flux is used in the soldering, connection failure is liable to occur. Metal plates can be used in place of the ground bars, but connection failure is liable to occur likewise because of using a flux in the soldering.
There is the problem that although, conventionally, the outer conductors of the coaxial cables are electrically connected and mechanically retained by the use of soldering, since wet solder goes along the outer conductors, the bendability of the coaxial cables is degraded in the range where the solder is raised. In order to solve this problem, the invention proposes a structure for connecting outer conductors of coaxial cables without using soldering.